With certain disorders, it is necessary to perform a surgical operation that consists in removing the downstream portion of the patient's intestine. The end of the portion of the intestine left in place is then brought out through the skin of the abdomen to constitute an artificial anus. However, under such circumstances, the patient can no longer control evacuation of matter. A collecting bag is thus placed at the artificial anus to receive matter as it flows out and to store it.
The bags most widely used at present include an adhesive base plate with a central opening. The base plate is attached to the bag so that its opening faces an opening of the bag that is formed in its back wall (i.e. the wall next to the skin). To keep the bag in place, the patient sticks the base plate to the skin around the artificial anus so that the anus is within the opening of the base plate, and is thus in communication with the inside of the collecting bag which can then receive matter.
In certain "one-piece" models of bag, the base plate is merely welded to the bag. In other, "two-piece" models, the base plate and the bag are adapted to be connected together by means of a coupling which can be opened and closed. That serves, in particular, to allow the base plate to remain in place while the bag is removed, e.g. to be changed.
Either way, wearing such bags can be painful. They are pressed relatively closely against the abdomen by clothing, and movements of the patient inevitably give rise to pushing and pulling on the artificial anus which often presents as an open wound. Efforts have therefore been made to provide such bags with padding to improve comfort.
One known form of bag is described in application EP 0 408 296. Its walls are constituted by a multilayer film of structure comparable to that of the bubble sheets lining the insides of padded envelopes. At regular intervals, the outer layers of the film are spaced apart from the inner layers so as to define air-filled cells or "bubbles" between them which project around the bag. As a result, the bag touches the skin of the patient only over the bubbles, thereby correspondingly reducing the area of contact with the skin and the resulting discomfort.
Another known form of bag is described in application GB 2 139 501. Its front wall (clothing side) and its back wall (skin side) are separated internally by an intermediate wall that is impermeable to liquids, but permeable to gases. This prevents the collected matter that penetrates through the opening in the back wall of the bag from coming into contact with the front wall. However it does allow gases to pass to the front wall which includes a vent filter. There is thus no risk of the filter becoming clogged with matter. In one embodiment, the intermediate wall occupies only the top portion of the bag and its bottom edge is welded to the front wall of the bag. Advantageously, foam is disposed in the chamber made in this way. That application specifies that the foam then acts as padding, making the bag more comfortable.
The drawback of those known forms of bag is that the bag is also padded around the artificial anus. This gives rise to pressure, in particular pressure exerted by clothing, that bears directly on the artificial anus, even if it does so through padding and is therefore somewhat damped.
Another known form of bag is described in patent U.S. Pat. No. 3,902,496 which mitigates the above drawback by avoiding pressure being applied directly to the artificial anus. To this end, it includes two cushions both extending vertically and situated on either side of the opening of the bag. The cushions are advantageously formed in an intermediate wall of the bag which is folded over and welded. They may be filled with air at atmospheric pressure, for example.
A drawback of the above known form of bag, that also applies to the preceding forms, is that the thickness of the padding cannot be changed. Unfortunately, the shape of an artificial anus can vary widely between patients. Some patients, e.g. having an invaginated anus, will want considerable thickness of padding, while others will want little extra thickness.